Commensal Hafnia alvei strain reduces food intake and fat mass in obese mice—a new potential probiotic for appetite and body weight management

Background/objectives Based on the recent identification of E.coli heat shock protein ClpB as a mimetic of the anorexigenic α-melanocyte stimulating hormone (α-MSH), the objective of this study was to preclinically validate Hafnia alvei , a ClpB-producing commensal bacterium as a potential probiotic for appetite and body weight management in overweight and obesity. Methods The involvement of enterobacterial ClpB in the putative anti-obesity effects was studied using ClpB-deficient E.coli . A food-grade H. alvei HA4597 strain synthetizing the ClpB protein with an α-MSH-like motif was selected as a candidate probiotic to be tested in ob/ob and high-fat diet (HFD)-fed obese and overweight mice. The relevance of the enterobacterial ClpB gene to human obesity was studied by in silico analysis of fecal metagenomes of 569 healthy individuals from the “MetaHIT” database. Results Chronic per os administration of native but not ClpB-deficient E.coli strain reduced body weight gain ( p